Micro-fluid ejection devices continue to be used in a wide variety of applications, including ink jet printers, medical delivery devices, micro-coolers and the like. Of the uses, ink jet printers provide, by far, the most common use of micro-fluid ejection devices. Ink jet printers are typically more versatile than laser printers for some applications. As the capabilities of ink jet printers are increased to provide higher quality images at increased printing rates, fluid ejection heads, which are the primary printing components of ink jet printers, continue to evolve and become more complex.
As the complexity of micro-fluid ejection devices increases, there is a need to include more functions on semiconductor substrates for the devices. However, there is a competing need to maintain or reduce the size of the substrates so as to minimize the cost of the ejection devices. While miniaturization provides benefits relative to material costs, such miniaturization may also have negative effects on operational properties of the devices. For example, reducing the size of ground and power busses on the substrate may enable smaller size substrates to be used. However, reduced size busses usually have higher resistance and thus generate more heat than larger busses. Hence, there continues to be a need for improved substrate conductor routing and layouts that do not adversely affect the electrical properties of the circuits.